Cutter chain



M P. HOLMES CUTTER HAIN May 5, 1936.

Filed May 29, 1953 2 Sheets-Sheet l l W m W WIMW N MW May 5, 1936. 'M. P. HOLMES CUTTER CHAIN Filed May 29, 1955 2 Sheets-Sheet 2 inveaziamjilamu'sPfihZmas:

Patented May 5, 1936 UNITED STATES PATENT OFFICE CUTTER CHAIN Massachusetts Application May 29, 1933, Serial No. 673,491

21 Claims.

This invention relates to cutter chains, and more particularly to improvements in cutter chains especially designed to use with coal cutting machines.

An object of this invention is to provide an improved cutter chain. A further object is to provide an improved cutter chain having improved bit holding means. A still further object is to provide an improved cutter bit for a cutter chain. Still another object is to provide an improved cutter chain especially designed to use with a narrow cutter bar for cutting relatively narrow kerfs. These and other objects of the invention will, however, hereinafter more fully appear.

In the accompanying drawings there are shown for purposes of illustration two forms which the invention may assume in practice.

In these drawings,

Fig. l is a side elevational view of one illustrative embodiment of the improved cutter chain, parts being shown in section to show structural details.

Fig. 2 is a cross sectional view taken substantially on line 22 of Fig. 1.

Fig. 3 is a perspective view of a cutter chain block.

Fig. 4 is a perspective view of the improved cutter bit.

Fig. 5 is a perspective view showing one of the cutter bit clamps.

Fig. 6 is a view similar to Fig. 1 showing a modi- 'fied form of construction.

Fig. 7 is a cross sectional view taken substantially on line 1-1 of Fig. 6.

Fig. 8 is a perspective view showing a modified form of cutter bit.

In the illustrative embodiment of the invention shown in Figs. 1 to 5, inclusive, there is shown a cutter chain generally designated I of 'a relatively narrow construction associated with a relatively narrow cutter bar 2. The improved cutter chain comprises a series of chain blocks 3 having inwardly projecting ears 4 carrying pins 5.

Pivotally connected to the pins 5 and disposed between the ears '4 of the chain blocks are central straps B for connecting the chain blocks together.

The chain blocks are provided with lateral guide surfaces 1 engaging the outer guiding edges 8 of the cutter bar, and the cutter bar is provided about its margin with a groove or slot 9 which presents a guiding surface engageable with the inner guide surfaces of the ears and straps of the chain. It will thus be seen that by this im- 55 proved arrangement of the ears and straps and the associated cutter bar, a cutter bar and chain of relatively narrow construction is obtained.

The preferred form of cutter bit II] is herein in the form of a barbed element generally triangular in shape, except for its indented base, and present- .5 ing oppositely disposed cutting points II and I2 and relatively inclined sides I3 and I4 converging inwardly toward the point I5 of the barbed element. The cutting points II and I2 have relatively inclined cutting faces I6 and I1 con- 10 verging inwardly toward the median line of the bit. The body of the bit is rectangular in cross section. Each chain block 3 is provided with a longitudinal slot I8 for receiving the body of the cutter bit, and the bit block is provided with a 15 longitudinal bore I9 for receiving a holding bolt 20. The ends of the bolt are provided with adjustable nuts 2 I, 2! for engaging clamp elements Y22 and 23 arranged at the opposite ends of the bit block, as shown in Fig. 1. The clamping ele- 20 ment 22 is provided with an inward projection 24 having an inclined surface 25 engageable with a corresponding inclined surface 26 on the bit block and the inclined surface I6 of the bit, while the clamping element 23 is provided with an inward 25 projection 21 having an inclined surface 28 engageable with the inclined surface I4 of the bit.

It will thus be seen that when the nuts on the bolt 20 are tightened the clamping elements are forced inwardly, thereby clamping the bit within the slot 30 I8 in the bit block.

When the cutting point I I of the cutter bit becomes dull, the nuts on the bolt 20 may be loosened, thereby releasing the clamping elements 22, 23 to permit removal of the cutter bit from 3' the slot I8 in the bit block. The bit is then turned over withits opposite edge inserted within the slot I8 and the clamping elements thereafter tightened into bit holding position, the cutting point I2 at that time being active while the inclined surface I4 of the bit engages the plane inner surface of the slot l8.

On links upon which the bit is not in the median plane of the chain, the surfaces 26 and the slots I8 may be properly rearranged so that 545 the planes of the surfaces 26 will be perpendicular to the lateral walls of the slots. The members 22 and 23 may be turned about the axis of their holding member 20 to proper position, and may be formed with transversely curved tops to preclude projection undesirably above the tops of the link members 3. It is obviously possible to make the surfaces 26 frusto-conical and to make the surfaces 25, 28 also frusto-conically concave, but this, while enabling variation in slot posi- 555 tion conveniently, involves making the cutting surfaces l6, l1 curved to permit proper cooperation with the concave surfaces corresponding to surfaces 25, 28. Obviously also offset bitcarrying links may be employed, and the bitcarrying head portions and the clamp elements formed as on the link shown, with the off-setting taking care of the bit position, the bit remaining central of the head on each link.

In the modification shown in Figs. 6, '7, and 8, the cutter chain is generally designated 30 and the cutter bar 3 l. The cutter chain comprises a series of bit blocks 32 each having at its outer sides inwardly projecting ears 33. Fixed within alined openings 34 formed in the ears 33 are rivets 35, while arranged between the ears 38 and pivotally connected to these rivets are side straps 35, 36 for connecting the bit blocks together. Mounted on the rivets 35 and interposed between the side straps 36, 36 are rollers 31 for engaging the inner guiding surface 38 of the cutter bar 3|. Formed at the sides of the cutter bar are stepped guiding surfaces 39 and 40 with which the straps 36 and ears 33 of the chain respectively cooperate in the guiding of the chain about the margin of the cutter bar. Each bit block is provided with a series of longitudinal slots 4|, herein three in number, arranged radially about a bore 42 extending longitudinally through the bit block. These slots are provided with circular enlargements 43 at their inner sides for the reception of the cylindrical body 44 of the improved cutter bit shown in Fig. 8. Extending centrally through the bore 42 of the bit block is a holding bolt 45 having threaded on its ends adjustable nuts 46, 46 engageable with annular clamping elements 41 and 48 mounted on the bolt, these clamping elements being held tightly against the opposite ends of the bit block by the holding bolt. These clamping elements 47, 48 also engage the opposite end surfaces of the cylindrical body 44 of the cutter bit in the manner shown in Fig. 6, thereby to hold the cutter bits in position within the bit receiving slots 4|. This modified form of cutter bit is provided with but a single cutting point 49 having an inwardly and rearwardly inclined cutting face 5|! and a rearwardly and inwardly inclined outer surface 5|, these faces terminating at the opposite end surfaces 52 and 53 respectively of the bit body. The surfaces 50 and El converge outwardly and forwardly to form the cutting point 49.

When it is desired to release the cutter bits from the bit block the holding bolt 45 may be loosened and the clamping elements 41, 48 removed therefrom, thereby to permit axial release of the cylindrical bodies 44 from the bit receiving slots 4!. When the bits become dull and have been removed from the bit block new bits may be readily inserted within the bit receiving slots in the bit block and held in position therein by tightening the holding bolt to bring the clamping elements into engagement with the opposite ends of the bit body.

As a result of this invention, it will be noted that an improved cutter chain is provided having an improved arrangement and formation whereby a relatively narrow cutter chain and cutter bar construction is attained. It will further be noted that an improved cutter bit is provided having associated therewith improved bit holding means whereby the cutter bit is held in position on the cutter chain in an improved manner. These and other uses and advantages of the improved cutter chain will be clearly apparent to those skilled in the art.

While there are in this application specifically described two forms which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by' Letters Patent is:

1. A cutter bit in the form generally of a triangle whose base instead of being plane is made reentrant to provide relatively inclined cutting surfaces which cooperate with the sides of said triangle to provide barbs whose points are cutting points.

2. In a cutter chain, a bit block, a cutter bit in the form of an acute-angled isosceles triangle having a V-notched base, in side elevation, and rectangular in cross section, and having cutting points at the extremities of the legs of the triangle remote from its apex, and means for holding said bit in cutting position on said bit block with one of its cutting points in an outwardly projecting cutting position.

3. Bit holding means for holding a bit in a bit block comprising relatively adjustable clamping elements adjustable relative to the bit block in directions longitudinal of the latter to effect clamping, and engaging different surfaces of a cutter bit and having operating means by which they are simultaneously adjustable toward each other relative to the bit block to clamp the cutter bit in cutting position against a surface of the bit block.

4. Bit holding means for holding a bit in a bit block comprising relatively adjustable clamping elements adjustable relative to the bit block and engaging different surfaces of a cutter bit for holding the latter in cutting position against a surface of the bit block, and a holding bolt for adjusting said clamping elements operative to transmit force to each of the same directly to move them towards each other to effect clamping.

5. A cutter chain comprising a bit block having a longitudinal slot, a cutter bit receivable in said slot and held therein during cutting, a holding 7 bolt carried by said bit block, and a plurality of relatively adjustable clamping elements held in position with respect to the bit block by said holding bolt and engaging the cutter bit for holding the latter in said slot.

6. A cutter bit and holder comprising a bit having a cylindrical body portion and a relatively inclined laterally-offset cutting surface and a holder having a socket for receiving said cylindrical bit body and cooperating clamping means engaging the end surfaces of said cylindrical body.

'7. A cutter bit and holder comprising a bit having a cylindrical body portion and an integral lateral portion, said lateral portion having a cutting point formed thereon, and a holder having a socket for receiving said cylindrical bit body and cooperating clamping means engaging the end surfaces of said cylindrical body.

8. A cutter chain comprising a bit block having a longitudinal slot, a cutter bit receivable in said slot, and means for holding said bit in said slot including relatively adjustable holding ele ments arranged at the ends of said bit block and engaging opposite ends of said bit.

9. A cutter chain comprising a bit block having a series of longitudinal slots, cutter bits receivable in said slots, and means for holding said bits in position in said slots including clamping elements arranged at opposite ends of the bit block and engaging all of said bits.

10. A cutter chain comprising a bit block having a series of longitudinal slots, cutter bits receivable in said slots, and means for holding said bits in position in said slots including clamping elements arranged at opposite ends of the bit block and engaging all of said bits, and a single holding bolt for adjusting said clamping elements in clamping position.

11. A cutter chain comprising a bit block having a longitudinal slot and a parallel longitudinal bore, a cutter bit having a portion receivable in said slot and a cutting portion projecting outwardly from the bit block, clamping members adjustable relative to the bit block at the front and rear sides of the latter and having portions engaging portions of said cutter bit to retain said bit portion in said slot, and a holding bolt extending through said bore and engaging said clamping elements.

12. A cutter chain comprising a bit block having a longitudinal slot and a parallel longitudinal bore, a cutter bit having a portion receivable in said slot and a cutting portion projecting outwardly from the bit block, clamping members adjustable relative to the bit block at the front and rear sides of the latter and having portions engaging portions of said cutter bit to retain said bit portion in said slot, and a holding bolt extending through said bore and engaging said clamping elements, said clamping elements having openings through which said bolt extends and nuts adjustably threaded on the ends of said bolt and engaging the outer surfaces of said clamping elements.

13. A cutter chain comprising a bit block having a longitudinal slot, a cutter bit in the form of a barbed element having relatively incline-d cutting portions, one of the cutting portions of the bit receivable in said slot, and adjustable clamping means engaging opposite end portions of the bit for retaining said bit portion in said slot.

14. A cutter chain comprising a bit block having a longitudinal slot, a cutter bit having a cylindrical body portion and a relatively inclined lateral cutting portion, said cylindrical body portion receivable by endwise sliding movement within said slot, and adjustable clamping elements engaging the opposite ends of said cylindrical body portion for preventing longitudinal release of the bit from said slot.

15. A cutter chain comprising a bit block having a longitudinal slot, a cutter bit in the form of a barbed element having relatively inclined cutting portions, a portion of said bit receivable in said slot, and clamping means for holding said bit in said slot comprising a clamping element engaging a surface of one cutting portion and another clamping element engaging another surface of the other cutting portion.

16. A cutter bit generally in the form of an acute-angled isosceles triangle but having its base formed to provide a barb at each end of the latter, said bit having cutting points formed at its end remote from its apex one at the extremity of each barb.

17. A cutter bit in the form of an isosceles triangle but having its base formed to provide a barb at each end of the latter, said bit having cutting points formed at its end remote from its apex, and having further relatively inclined cutting faces terminating at said cutting points and converging at the median line of the isosceles triangle at a point between the base and apex thereof.

18. A cutter bit in the form, in side elevation, of an isosceles triangle having a triangle cut from its base portion, said bit providing cutting points at the extremities of the legs of the first mentioned triangle remote from the angle opposite its base, and further providing relatively inclined cutting faces converging at a line perpendicular to the base and passing through the apex of the mentioned triangle.

19. In a cutter chain, a cutter block having a longitudinal slot and bit holding means for holding a cutter bit in the bit block slot comprising relatively adjustable clamping elements adjustable relative to the bit block and respectively engaging different surfaces of the cutter bit to clamp the latter in position in said bit block slot.

20. A cutter bit in the form of an isosceles triangle in side elevation save that its base is relatively deeply indented, and rectangular in cross section and having cutting points at the extremities of the legs of the triangle remote from its apex, a straight line extending between said points being of substantially less length than the sides of the triangle.

21. A cutter bit in side elevation generally in the form of an isosceles triangle having its base line of substantially less length than its sides but having short angularly related lines in place of a straight base line and having cutting points at the extremities of the legs of the triangle remote from its apex.

MORRIS P. HOLMES. 

